CN109150405B - Video multicast transmission method based on TV white band - Google Patents

Video multicast transmission method based on TV white band Download PDF

Info

Publication number
CN109150405B
CN109150405B CN201811092063.9A CN201811092063A CN109150405B CN 109150405 B CN109150405 B CN 109150405B CN 201811092063 A CN201811092063 A CN 201811092063A CN 109150405 B CN109150405 B CN 109150405B
Authority
CN
China
Prior art keywords
video
user
resource scheduling
spectrum
quality
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201811092063.9A
Other languages
Chinese (zh)
Other versions
CN109150405A (en
Inventor
武明虎
刘猛
刘聪
岳寒桧
徐偲达
李帜
赵楠
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hubei University of Technology
Original Assignee
Hubei University of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hubei University of Technology filed Critical Hubei University of Technology
Priority to CN201811092063.9A priority Critical patent/CN109150405B/en
Publication of CN109150405A publication Critical patent/CN109150405A/en
Application granted granted Critical
Publication of CN109150405B publication Critical patent/CN109150405B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0002—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the transmission rate
    • H04L1/0003—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the transmission rate by switching between different modulation schemes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0009—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the channel coding
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/02—Details
    • H04L12/16—Arrangements for providing special services to substations
    • H04L12/18—Arrangements for providing special services to substations for broadcast or conference, e.g. multicast
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/169—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
    • H04N19/187—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being a scalable video layer
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/14—Spectrum sharing arrangements between different networks

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Quality & Reliability (AREA)
  • Multimedia (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

The invention discloses a video multicast transmission method based on a TV white band, which comprises five steps of building a wireless video multicast transmission network, carrying out SVC coding processing on a video by a CR base station, carrying out spectrum detection and realizing maximum resource scheduling. The invention improves the utilization rate of the white frequency band of the TV by using the cognitive radio technology, adopts the SVC technology to code the video to ensure that a user obtains the video matched with the channel quality of the video, adopts the AMC channel coding technology to be matched with the video coding SVC technology to ensure the link quality in the physical layer, proposes the maximum proportion fairness as the resource scheduling criterion, obtains the suboptimal solution of the optimal resource scheduling by using the heuristic algorithm of the binary particle swarm algorithm with lower complexity, solves the resource scheduling problem, improves the throughput and the video receiving quality of the system, and realizes the purpose of receiving the high-quality video matched with the user according to the channel quality of the user.

Description

Video multicast transmission method based on TV white band
Technical Field
The invention relates to the technical field of wireless communication, in particular to a video multicast transmission method based on a TV white space.
Background
In recent years, with the popularization of portable intelligent terminals such as smartphones and tablet computers, people are not limited to computers and televisions for watching videos, people tend to watch videos when taking a car, waiting for a plane or walking, and with the full-coverage application of 4G networks, mobile video data traffic occupies a larger proportion of all mobile data traffic.
The development of wireless video services requires a huge amount of bandwidth support, the current spectrum resources are seriously lack, a great part of reasons are from the increasing mobile multimedia application, and the further popularization of intelligent electronic products inevitably causes greater impact on the mobile communication network which is about to break down at present.
Under the circumstance, the carrier network of each mobile network operator is not sufficient, other non-video services such as mobile phone internet surfing, mail receiving and sending, and instant messaging are also in danger of serious broadband compression, and the TV white band is utilized to carry video transmission service with huge broadband consumption, so that the increasingly serious problem of spectrum resource shortage in the field of wireless communication can be relieved on one hand, and the TV white band can be fully utilized on the other hand.
The video unicast transmission method allocates a separate channel resource to each user to transmit video data, and consumes a large amount of broadband resources. Therefore, the above problems are solved in a multicast mode, wireless video multicast firstly needs to perform source coding to reduce the data volume to be transmitted, with the rapid development of video coding technology, h.264/MPEG-4AVC can provide a good compression ratio, but the application of these technologies makes video become a very harsh application, which is very sensitive to errors such as packet loss and bit error, the current video coding cannot be directly used for wireless video transmission, because the fixed code stream code rate output by the coding scheme is different in the wireless video transmission, the channel quality of users is different, the coding mode of the fixed code stream code rate can only select the code rate that the user can bear in order to consider the user with poor channel quality, the mode is unfair for the user with good channel quality, the current wireless video technology is supported by the video coding of an application layer and the physical channel coding, and under the guidance of a protocol layer design concept, the two layers of technologies are independently researched and set, which also results in the lack of robustness and expandability of wireless video transmission.
Disclosure of Invention
The present invention is directed to solving, at least in part, one of the technical problems in the related art. Therefore, an object of the present invention is to provide a video multicast transmission method based on TV white bands, which can improve throughput and received video quality, and ensure that users receive video matching their channel quality.
The video multicast transmission method based on the TV white band according to the embodiment of the invention comprises the following steps:
step 1: building a wireless video multicast transmission network and setting basic parameters;
step 2: the CR base station performs SVC coding processing on the video: the CR base station uses SVC technology to encode video, the video is encoded into a basic layer and two enhancement layers, the basic layer is used to ensure the most basic video quality, the enhancement layers are used to improve the video quality, adaptive Modulation Coding (AMC) is adopted in the physical layer, each coding scheme is composed of a modulation scheme and a forward error correction scheme (FEC) with different coding rates, the coding schemes have different spectral efficiency (BUR), the higher the BUR of the general coding scheme is, the smaller the coverage range is, the channel coding scheme in M is arranged into [ MC ] according to the ascending order of coding efficiency 1 ，…，MC m ]And specifying that MC is adopted for m-th layer video after SVC encoding of any video m Sending is carried out;
and step 3: detection of wireless spectrum: directly sampling and modulus-solving the received time domain signal, and then solving the square of the time domain signal to obtain the signal;
and 4, step 4: selection of wireless spectrum: after the current UHF channel states are obtained, the base station performs spectrum selection operation to obtain an optimal working frequency band, binding operation is performed on a plurality of continuous available channels in the spectrum selection process to obtain a larger frequency band, and the larger the spectrum spanning degree is, the higher the probability that the system is interrupted by a main user is, so an attenuation factor eta epsilon (0, 1) is set in the spectrum selection process to limit the spectrum spanning degree, and the spectrum selection is summarized as the following problem mathematical expression:
Figure BDA0001804612800000021
s.t:π i ＝1，i＝c+1,···,c+l；
where B is i Indicating the bandwidth of channel i; typically, UHF channels have the same bandwidth, i.e. B 1 ＝B 2 ＝···＝B i ；
And 5: and (3) realizing optimal resource scheduling: in order to further improve the quality of the integrally received video, the invention uses a cross-layer optimized subcarrier scheduling mechanism, namely when new subcarrier spectrum sensing data is obtained, the subcarrier scheduling mechanism is executed, so that the optimal allocation of wireless spectrum can be realized, and the user is ensured to obtain video resources matched with the channel quality of the user.
Preferably, the specific steps of establishing the wireless video multicast transmission network in the step 1 are as follows: considering a centralized single-hop CR network to match with a plurality of main networks, wherein the main networks have the right of preferentially using UHF frequency bands, and because of the transmission of a main user, the availability of each UHF frequency band changes along with the time, the CR network consisting of N mobile CR users and CR base stations can be accessed into the UHF frequency bands opportunistically on the premise of not interfering the main user, and if the base stations are provided with S omnidirectional antennas with adjustable width, which are independent from each other and work on different frequency bands, each CR user is also provided with a widely adjustable antenna, and can communicate with the base station in any UHF frequency band;
given C UHF channels, each with a bandwidth of B, which is a potential candidate for opportunistic access by the CR system, a subset of UHF channels can potentially be accessed by CR user i at a particular time depending on its current location. The information can be composed of
Figure BDA0001804612800000031
Represents:
Figure BDA0001804612800000032
to prevent "secondary interference" caused by simultaneous access of multiple CR systems to available channels, such interference is not fatal, but is nonethelessStill have a severe impact on cognitive communication, therefore, the present invention introduces an additional channel metric, called the desired signal to interference plus noise ratio
Figure BDA0001804612800000033
The definition is as follows:
Figure BDA0001804612800000034
P i indicates the received power of CR user i and,
Figure BDA0001804612800000035
is the value of i secondary interference power heard from UHF channel c, N 0 Is additive white gaussian noise.
Preferably, the specific steps for implementing the optimal resource scheduling in step 5 are as follows:
step 5.1: let the obtained frequency band be F and the span be W F The system adopts Orthogonal Frequency Division Multiplexing (OFDM) modulation mode to access the acquired frequency band, and each subcarrier has a frequency width of (f, the system has K = ζ BW altogether F A/Δ f subcarriers, where ζ represents an OFDM frequency reuse factor; let K =1, \8230, K denotes the subcarrier sequence number, and the snr of user i on subcarrier K is γ i,k For each multicast group g, a user set which can correctly receive the video layer m on the subcarrier k is obtained:
L g,m,k ＝{i|i∈N g ,Υ m ＜γ i,k ＜Υ m+1 }；
define the rate set of video g as R g ＝{v g,1 ,...,v g,M Here, at this point
Figure BDA0001804612800000041
Step 5.2: in the resource scheduling process, in order to determine the optimal mapping relationship between the subcarrier sequence {1, \8230;, K } and each video layer {1, \8230;, M } of each video program {1, \8230;, G } and to determine the optimal MCS scheme for each subcarrier, the adopted resource scheduling criterion is the maximized proportional fairness, that is, it is ensured that each user obtains the video quality matched with its channel condition as much as possible, and the resource scheduling criterion is formulated as follows:
Figure BDA0001804612800000042
step 5.3: given a resource allocation matrix L, solving the problem that the MCS scheme MC can be correctly received in the multicast group g m Total number of nodes encoding data
Figure BDA0001804612800000043
Figure BDA0001804612800000044
Here, the
Figure BDA0001804612800000045
Representation collection
Figure BDA0001804612800000046
The total number of nodes contained in (1), thereby obtaining:
Figure BDA0001804612800000047
here, the number of the first and second electrodes,
Figure BDA0001804612800000048
represents the reception quality of the user as follows:
Figure BDA0001804612800000049
since the underlying spectrum resources are derived from the result of the instant sensing and have high uncertainty, the following two cases must be considered in the resource scheduling process:
when in use
Figure BDA00018046128000000410
The underlying spectrum resources are sufficient to support the transmission of all video layers, without considering the underlying preferential allocation limit and the lowest rate limit, so the optimal resource scheduling problem can be expressed mathematically as follows:
Figure BDA0001804612800000051
Figure BDA0001804612800000052
Figure BDA0001804612800000053
when the temperature is higher than the set temperature
Figure BDA0001804612800000054
Then, the underlying spectrum resources are not enough to support the transmission of all video layers, and the underlying preferential allocation limit and the lowest rate limit must be considered, so the optimal resource scheduling problem in this case is expressed mathematically as follows:
Figure BDA0001804612800000055
Figure BDA0001804612800000056
Figure BDA0001804612800000057
Figure BDA0001804612800000058
Figure BDA0001804612800000059
step 5.4: solving by using a binary particle swarm algorithm: firstly, initializing parameters, in the initialization process, firstly giving the initial positions of the particles and the initial speed of each particle
Figure BDA00018046128000000510
According to omega t Updating the particle speed:
Figure BDA00018046128000000511
updating the particle position according to the iteration index t:
Figure BDA00018046128000000512
when the iteration reaches the preset maximum iteration algorithm, the optimal solution of resource scheduling is obtained, the optimal distribution of the sub-carriers is realized, and the wireless video multicast quality is optimized.
The beneficial effects of the invention are as follows: the invention improves the utilization rate of the white frequency band of the TV by using the cognitive radio technology, adopts the SVC technology to code the video to ensure that a user obtains the video matched with the channel quality of the video, adopts the AMC channel coding technology to be matched with the video coding SVC technology to ensure the link quality in the physical layer, proposes the maximum proportion fairness as the resource scheduling criterion, obtains the suboptimal solution of the optimal resource scheduling by using the heuristic algorithm of the binary particle swarm algorithm with lower complexity, solves the resource scheduling problem, improves the throughput and the video receiving quality of the system, and realizes the purpose of receiving the high-quality video matched with the user according to the channel quality of the user.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:
fig. 1 is a general flowchart of a video multicast transmission method based on TV white bands according to the present invention;
fig. 2 is a structural diagram of a video multicast based on TV white space according to the present invention;
fig. 3 is a flowchart illustrating energy detection of a video multicast transmission method based on TV white bands according to the present invention;
fig. 4 is a flow chart of a binary particle swarm algorithm of a video multicast transmission method based on a TV white space band according to the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.
Referring to fig. 1-4, a video multicast transmission method based on TV white space includes the following steps:
step 1: building a wireless video multicast transmission network, and setting basic parameters: considering a centralized single-hop CR network to match with a plurality of main networks, wherein the main networks have the right of preferentially using UHF frequency bands, and because of the transmission of a master user, the availability of each UHF frequency band changes along with the time, the CR network consisting of N mobile CR users (consisting of a CR user set N) and CR base stations can access the UHF frequency bands opportunistically on the premise of not interfering the master user, and assuming that the base stations are provided with S omnidirectional antennas with adjustable widths, the S omnidirectional antennas are mutually independent and work on different frequency bands, each CR user is also provided with a widely adjustable antenna, and can communicate with the base stations in any UHF frequency band;
assuming C UHF channels, each with a bandwidth of B, a potential candidate for opportunistic access by the CR system, a subset of UHF channels can potentially be accessed by CR user i at a particular time depending on its current location. The information can be composed of
Figure BDA0001804612800000071
Represents:
Figure BDA0001804612800000072
to prevent "secondary interference" caused by simultaneous access of multiple CR systems to available channels, which interference is not fatal but still has a severe impact on cognitive communication, the present invention introduces an additional channel metric, called the desired signal-to-interference-and-noise ratio
Figure BDA0001804612800000073
The definition is as follows:
Figure BDA0001804612800000074
P i indicates the received power of CR user i and,
Figure BDA0001804612800000075
is the value of i secondary interference power heard from UHF channel c, N 0 Is additive white Gaussian noise;
step 2: the CR base station performs SVC coding processing on the video: a CR base station encodes a video by using an SVC technology, the video is encoded into a base layer and two enhancement layers, the base layer is used for ensuring the most basic video quality, the enhancement layers are used for improving the video quality, adaptive Modulation Coding (AMC) is adopted in a physical layer, each coding scheme consists of a modulation scheme and a forward error correction scheme (FEC) with different coding rates, and the CR base station has different spectral efficiencies (BURs), for example, a combination of a Quadrature Phase Shift Keying (QPSK) modulation scheme and an FEC scheme with a code rate of 1/2 has a BUR of 1, and a combination of an octal quadrature amplitude modulation scheme (QAM-64) and an FEC scheme with a code rate of 2/3 has a BUR of 4; the higher the BUR of a general coding scheme is, the smaller the coverage area is, and the M-channel coding schemes are arranged as [ MC ] according to the ascending order of coding efficiency 1 ，…，MC m ]And are combinedAnd the Mth layer video adopts MC after any video is subjected to SVC coding m Sending is carried out;
and 3, step 3: detection of wireless spectrum: the method has the advantages that the received time domain signal is directly sampled and subjected to modulus calculation, and then the square of the time domain signal is calculated, so that the energy detection can be obtained, and the energy detection does not need any prior information of a detection signal, so that the energy detection is very suitable for detecting the working state of a master user by a local sensing user in cognitive radio;
and 4, step 4: selection of wireless spectrum: after the current states of all UHF channels are obtained, a base station performs spectrum selection operation to obtain an optimal working frequency band, binding operation is performed on a plurality of continuous available channels in the spectrum selection process to obtain a larger frequency band, as the frequency spectrum spanning degree (namely the total number of UHF channels spanned by the frequency band) is larger, the probability that a system is interrupted by a main user is larger, an attenuation factor eta epsilon (0, 1) is set in the spectrum selection process to limit the frequency spectrum spanning degree, and the spectrum selection is summarized as the following problem mathematical expression:
Figure BDA0001804612800000081
s.t:π i ＝1，i＝c+1,···,c+l；
where B is i Indicating the bandwidth of channel i; typically, UHF channels have the same bandwidth, i.e. B 1 ＝B 2 ＝···＝B i ；
And 5: and (3) realizing optimal resource scheduling: in order to further improve the quality of the integrally received video, the invention uses a cross-layer optimized subcarrier scheduling mechanism, namely when new subcarrier spectrum sensing data is obtained, the subcarrier scheduling mechanism is executed, so that the optimal allocation of wireless spectrum can be realized, and the user is ensured to obtain video resources matched with the channel quality of the user;
let the obtained frequency band be F and the span be W F The system adopts Orthogonal Frequency Division Multiplexing (OFDM) modulation mode to access the acquired frequency band, and each subcarrier has a frequency width of (f, the system has K = ζ BW altogether F A/Δ f sub-carriers, hereζ represents an OFDM frequency reuse factor; let K =1, \ 8230;, K denotes the subcarrier number and the snr of user i on subcarrier K is γ i,k The multicast group, for each multicast group g,
and obtaining a user set which can correctly receive the video layer m on the subcarrier k:
L g,m,k ＝{i|i∈N g ,Υ m ＜γ i,k ＜Υ m+1 }；
define the rate set of video g as R g ＝{v g,1 ,...,v g,M Therein is here
Figure BDA0001804612800000082
In the resource scheduling process, in order to determine the optimal mapping relationship between the subcarrier sequence {1, \8230;, K } and each video program {1, \8230;, each video layer {1, \8230;, M } of G } and to determine the optimal Modulation and Coding Strategy (MCS) scheme for each subcarrier, the adopted resource scheduling criterion is the maximum proportional fairness, that is, it is ensured that each user obtains the video quality matched with its channel condition as much as possible, and the resource scheduling criterion is formulated as follows:
Figure BDA0001804612800000083
Q g,i representing a user i ∈ N g Received video quality, Q g,i It can also be written as follows:
Figure BDA0001804612800000091
Figure BDA0001804612800000092
representing the decoded video quality of the base layer of video g,
Figure BDA0001804612800000093
represents the cumulative enhancement layer rate, β, of the video g g With respect to specific video sequences and SVC coding parameters;
furthermore, according to the characteristics of the video stream and the practical transmission environment limit, a constraint rule in resource scheduling is defined, and for analysis, a three-dimensional binary matrix L = { L =isdefined g,m,k } G,M,K Here, the
l g,m,k =1 denotes that subcarrier k is allocated to mth video layer of video g, the constraint rule is as follows:
1. the only constraint is that: the uniqueness constraint specifies that a certain subcarrier can only be allocated to one multicast group for use, i.e. the subcarrier cannot be repeatedly allocated, and is formulated as follows:
Figure BDA0001804612800000094
2. layer integrity constraints: the layer integrity constraint means that when a certain video layer is transmitted, the system must provide enough subcarrier resources to support the transmission of the video layer, and the formula is expressed as follows:
Figure BDA0001804612800000095
3. low-layer priority allocation principle: since the high video layer in SVC needs to be decoded according to the information in the low video layer, we specify that the low video layer is preferentially allocated with subcarriers in the resource scheduling process, and the formula is expressed as follows:
Figure BDA0001804612800000096
4. minimum rate limiting: to ensure the minimum video quality for the user, we specify that the base layer of each video is preferentially allocated with subcarriers, and the formula is as follows:
Figure BDA0001804612800000097
further, according to the determined optimization criteria, given the resource allocation matrix L, the MCS scheme MC can be correctly received in the multicast group g m Total number of nodes of data to encode
Figure BDA0001804612800000098
Figure BDA0001804612800000099
Here, the
Figure BDA0001804612800000101
Representation collection
Figure BDA0001804612800000102
The total number of nodes contained in (1), thereby obtaining:
Figure BDA0001804612800000103
here, the first and second liquid crystal display panels are,
Figure BDA0001804612800000104
represents the reception quality of the user as follows:
Figure BDA0001804612800000105
since the underlying spectrum resources are derived from the result of the instant sensing and have high uncertainty, the following two cases must be considered in the resource scheduling process:
when in use
Figure BDA0001804612800000106
The underlying spectral resources are sufficient to support the transmission of all video layers, regardless of underlying preferential allocation constraints and minimum ratesThe constraint, and therefore the optimal resource scheduling problem, can be expressed mathematically as follows:
Figure BDA0001804612800000107
Figure BDA0001804612800000108
Figure BDA0001804612800000109
when in use
Figure BDA00018046128000001010
Then, the underlying spectrum resources are not enough to support the transmission of all video layers, and the underlying preferential allocation limit and the lowest rate limit must be considered, so the optimal resource scheduling problem in this case is expressed mathematically as follows:
Figure BDA00018046128000001011
Figure BDA00018046128000001012
Figure BDA0001804612800000111
Figure BDA0001804612800000112
Figure BDA0001804612800000113
furthermore, according to the high requirement of the video service on the delay, the algorithm with high efficiency and low complexity is required for optimal resource scheduling; the invention provides a heuristic algorithm of a binary particle swarm algorithm to obtain a solution of optimal resource scheduling;
in particle swarm optimization, each possible solution is represented as a particle, two attributes (position and velocity) are associated with each particle, and the optimal position of the ith particle in the D-dimensional search space is represented as X i ＝[x i1 ,...,x iD ]，V i ＝[v i1 ,...,v iD ]Each element has a practical value, such that
Figure BDA0001804612800000114
And
Figure BDA0001804612800000115
is the optimal position (with the best fitness value) for the ith particle, the velocity and position for each particle is updated as follows:
Figure BDA0001804612800000116
Figure BDA0001804612800000117
where ω is called the inertial weight, which controls the influence of the last velocity of the particle on the current particle, c 1 c 2 Is a normal number and becomes an acceleration coefficient, r 1 r 2 Are uniformly distributed in [0,1 ]]And t represents an iteration index;
applying high inertia weight when the algorithm starts, weakening the weight through a binary particle swarm algorithm, searching globally when the algorithm search starts, and searching locally when the algorithm search ends, wherein the inertia weight omega is as follows:
Figure BDA0001804612800000118
the velocity of the d-th element in the ith particle is related to the probability that the position of the particle takes on a value of 1 or 0 by defining a variable called an intermediate variable
Figure BDA0001804612800000119
A Sigmoid constrained transform, as follows:
Figure BDA00018046128000001110
further solving by using a binary particle swarm algorithm: firstly, initializing parameters, in the initialization process, firstly giving the initial position of the particles and the initial speed of each particle
Figure BDA0001804612800000121
According to omega t Updating the particle speed:
Figure BDA0001804612800000122
updating the particle position according to the iteration index t:
Figure BDA0001804612800000123
when the iteration reaches the termination of the preset maximum iteration algorithm, the optimal solution of resource scheduling is obtained, the optimal allocation of subcarriers is realized, and the wireless video multicast quality is optimized.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered as the technical solutions and the inventive concepts of the present invention within the technical scope of the present invention.

Claims (2)

1. A video multicast transmission method based on TV white space is characterized in that: the method comprises the following steps:
step 1: building a wireless video multicast transmission network and setting basic parameters;
and 2, step: the CR base station performs Scalable Video Coding (SVC) processing on the video: the CR base station uses SVC technology to encode video, the video is encoded into a basic layer and two enhancement layers, the basic layer is used to ensure the most basic video quality, the enhancement layers are used to improve the video quality, adaptive Modulation Coding (AMC) is adopted in the physical layer, each coding scheme is composed of a modulation scheme and a forward error correction scheme (FEC) with different coding rates, the coding schemes have different spectral efficiency (BUR), the higher the BUR of the general coding scheme is, the smaller the coverage range is, the channel coding scheme in M is arranged into [ MC ] according to the ascending order of coding efficiency 1 ，…，MC m ]And specifying that MC is adopted for m-th layer video after SVC encoding of any video m Sending is carried out;
and step 3: detection of wireless spectrum: directly sampling and modulus solving are carried out on the received time domain signal, and then the square of the time domain signal is solved;
and 4, step 4: selection of wireless spectrum: after the current state of each ultrahigh frequency radio wave (UHF) channel is obtained, the base station performs spectrum selection operation to obtain an optimal working frequency band, binding operation is performed on a plurality of continuous available channels in the spectrum selection process to obtain a larger frequency bandwidth, and the larger the spectrum spanning degree is, the higher the probability that the system is interrupted by a main user is, so an attenuation factor eta epsilon (0, 1) is set in the spectrum selection process to limit the spectrum spanning degree, and the spectrum selection is summarized as the following problem mathematical expression:
max:
Figure FDA0003794336350000011
s.t:π i ＝1，i＝c+1,···,c+l；
where B is i Indicating the bandwidth of channel i; UHF channels having the same bandwidth, i.e. B 1 ＝B 2 ＝…＝B i ；
And 5: and (3) realizing optimal resource scheduling: in order to further improve the quality of the integrally received video, a cross-layer optimized subcarrier scheduling mechanism is used, namely when new subcarrier spectrum sensing data are obtained, the subcarrier scheduling mechanism is executed, so that optimal wireless spectrum allocation can be realized, and a user is ensured to obtain video resources matched with the channel quality of the user;
the specific steps for realizing the optimal resource scheduling in the step 5 are as follows:
step 5.1: let the acquired frequency band be F and the span be W F The system adopts an Orthogonal Frequency Division Multiplexing (OFDM) modulation method to access the acquired frequency band, and each subcarrier has a bandwidth Δ f, so that the system has K = ζ BW F A/Δ f subcarriers, where ζ represents an OFDM frequency reuse factor; let K =1, \8230, K denotes the subcarrier sequence number, and the snr of user i on subcarrier K is γ i,k For each multicast group g, a user set which can correctly receive the video layer m on the subcarrier k is obtained:
L g,m,k ＝{i|i∈N g ,Υ m ＜γ i,k ＜Υ m+1 }；
define the rate set of video g as R g ＝{v g,1 ,...,v g,M Here, at this point
Figure FDA0003794336350000021
And step 5.2: in the resource scheduling process, in order to determine the optimal mapping relationship between the subcarrier sequence {1, \8230;, K } and each video layer {1, \8230;, M } of each video program {1, \8230;, G } and to determine the optimal MCS scheme for each subcarrier, the adopted resource scheduling criterion is the maximized proportional fairness, that is, it is ensured that each user obtains the video quality matched with its channel condition as much as possible, and the resource scheduling criterion is formulated as follows:
Figure FDA0003794336350000022
step 5.3: given a resource allocation matrix L, solving the problem that the MCS scheme MC can be correctly received in the multicast group g m Total number of nodes encoding data
Figure FDA0003794336350000023
Figure FDA0003794336350000024
Here, the
Figure FDA0003794336350000025
Representation collection
Figure FDA0003794336350000026
The total number of nodes contained in (1), thereby obtaining:
Figure FDA0003794336350000027
here, the number of the first and second electrodes,
Figure FDA0003794336350000028
represents the reception quality of the user, as follows:
Figure FDA0003794336350000029
since the underlying spectrum resources are derived from the result of the instant sensing and have high uncertainty, the following two cases must be considered in the resource scheduling process:
when in use
Figure FDA0003794336350000031
The underlying spectrum resources are sufficient to support the transmission of all video layers, without considering the underlying preferential allocation limit and the lowest rate limit, so the optimal resource scheduling problem can be expressed mathematically as follows:
max:
Figure FDA0003794336350000032
s.t.:
Figure FDA0003794336350000033
Figure FDA0003794336350000034
when in use
Figure FDA0003794336350000035
Then, the underlying spectrum resources are not enough to support the transmission of all video layers, and the underlying preferential allocation limit and the lowest rate limit must be considered, so the optimal resource scheduling problem in this case is expressed mathematically as follows:
max:
Figure FDA0003794336350000036
s.t.:
Figure FDA0003794336350000037
Figure FDA0003794336350000038
Figure FDA0003794336350000039
Figure FDA00037943363500000310
step 5.4: solving by using a binary particle swarm algorithm: firstly, initializing parameters, in the initialization process, firstly giving the initial position of the particles and the initial speed of each particle
Figure FDA00037943363500000311
According to omega t Updating the particle speed:
Figure FDA00037943363500000312
updating the particle position according to the iteration index t:
Figure FDA0003794336350000041
when the iteration reaches the preset maximum iteration algorithm, the optimal solution of resource scheduling is obtained, the optimal distribution of the sub-carriers is realized, and the wireless video multicast quality is optimized.
2. The multicast transmission method for video based on TV white spaces according to claim 1, wherein: the specific steps of building the wireless video multicast transmission network in the step 1 are as follows: considering a centralized single-hop CR network to be matched with a plurality of main networks, wherein the main networks have the right of preferentially using UHF frequency bands, because the transmission of a main user, the availability of each UHF frequency band changes along with the time, the CR network consisting of N mobile CR users and a CR base station can be accessed into the UHF frequency bands opportunistically on the premise of not interfering the main user, and assuming that the base station is provided with S omnidirectional antennas with adjustable width, the omnidirectional antennas are mutually independent and work on different frequency bands, each CR user is also provided with a widely adjustable antenna, and can communicate with the base station in any UHF frequency band;
assuming C UHF channels, each with a bandwidth of B, are potential candidates for opportunistic access by the CR system, a subset of UHF channels can potentially be accessed by CR user i at a particular time, depending on its current location
Figure FDA0003794336350000042
Represents:
Figure FDA0003794336350000043
to prevent "secondary interference" caused by simultaneous access of multiple CR systems to available channels, which interference is not fatal but still has a severe impact on cognitive communication, an additional channel metric, called the desired signal-to-interference-and-noise ratio, is introduced
Figure FDA0003794336350000044
The definition is as follows:
Figure FDA0003794336350000045
P i indicates the received power of CR user i and,
Figure FDA0003794336350000046
is i secondary interference power value, N, heard from UHF channel c 0 Is additive white gaussian noise.
CN201811092063.9A 2018-09-19 2018-09-19 Video multicast transmission method based on TV white band Active CN109150405B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201811092063.9A CN109150405B (en) 2018-09-19 2018-09-19 Video multicast transmission method based on TV white band

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201811092063.9A CN109150405B (en) 2018-09-19 2018-09-19 Video multicast transmission method based on TV white band

Publications (2)

Publication Number Publication Date
CN109150405A CN109150405A (en) 2019-01-04
CN109150405B true CN109150405B (en) 2022-11-29

Family

ID=64814966

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201811092063.9A Active CN109150405B (en) 2018-09-19 2018-09-19 Video multicast transmission method based on TV white band

Country Status (1)

Country Link
CN (1) CN109150405B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113115236B (en) * 2021-03-29 2022-03-15 北京航空航天大学 Low-complexity multicast group decomposition method based on SVC video stream
CN114786137B (en) * 2022-04-21 2023-06-20 重庆邮电大学 Cache-enabled multi-quality video distribution method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103857046A (en) * 2014-03-06 2014-06-11 南京理工大学 Self-adaptive resource distribution method of cognition OFDM network based on spectrum filling
CN104661047A (en) * 2015-03-09 2015-05-27 中国科学技术大学 Method and system for transmitting scalable coded videos in heterogeneous cellular network
CN105007541A (en) * 2015-07-29 2015-10-28 上海交通大学 Scalable video stream dynamic multi-rate multicast optimal transmission method
CN105406945A (en) * 2015-11-25 2016-03-16 合肥工业大学 Multicast resource distribution and transmission method for scalable video in system with multiple base stations

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10616383B2 (en) * 2016-09-26 2020-04-07 Samsung Display Co., Ltd. System and method for electronic data communication

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103857046A (en) * 2014-03-06 2014-06-11 南京理工大学 Self-adaptive resource distribution method of cognition OFDM network based on spectrum filling
CN104661047A (en) * 2015-03-09 2015-05-27 中国科学技术大学 Method and system for transmitting scalable coded videos in heterogeneous cellular network
CN105007541A (en) * 2015-07-29 2015-10-28 上海交通大学 Scalable video stream dynamic multi-rate multicast optimal transmission method
CN105406945A (en) * 2015-11-25 2016-03-16 合肥工业大学 Multicast resource distribution and transmission method for scalable video in system with multiple base stations

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Energy-Efficient Adaptive Transmission of Scalable Video Streaming in Cognitive Radio Communications;Qi Jiang;《IEEE》;20150601;全文 *

Also Published As

Publication number Publication date
CN109150405A (en) 2019-01-04

Similar Documents

Publication Publication Date Title
Afolabi et al. Multicast scheduling and resource allocation algorithms for OFDMA-based systems: A survey
CN105409260B (en) System and method for user equipment cooperation
JP2006067572A (en) Method for assigning sub-channel in radio network
CN107979824B (en) D2D multicast resource allocation method in wireless network virtualization scene
US7856004B2 (en) Method for scheduling heterogeneous traffic in B3G/4G cellular networks with multiple channels
CN107343268B (en) Non-orthogonal multicast and unicast transmission beamforming method and system
Guo et al. Fairness-aware energy-efficient resource allocation in D2D communication networks
CN109150405B (en) Video multicast transmission method based on TV white band
CN112566261A (en) Deep reinforcement learning-based uplink NOMA resource allocation method
CN112367523B (en) Resource management method in SVC multicast based on NOMA in heterogeneous wireless network
US8374101B2 (en) Multicast with joint layer resource allocation in broadband wireless networks
Chehri et al. Real‐time multiuser scheduling based on end‐user requirement using big data analytics
Dani et al. Power allocation for layered multicast video streaming in non-orthogonal multiple access system
CN106851726A (en) A kind of cross-layer resource allocation method based on minimum speed limit constraint
CN110611525A (en) Signal transmission and receiving method and device based on rate splitting
Zeng et al. Downlink power allocation optimization in pattern division multiple access
Kallel et al. A flexible numerology configuration for efficient resource allocation in 3GPP V2X 5G new radio
Masaracchia et al. On the optimal user grouping in NOMA system technology
Li et al. Transmission schemes for multicarrier broadcast and unicast hybrid systems
CN109286480B (en) Subcarrier distribution method for orthogonal frequency division multiple access system based on candidate channel matching method
Hindumathi et al. A proficient fair resource allocation in the channel of multiuser orthogonal frequency division multiplexing using a novel hybrid bat-krill herd optimization
Valadão et al. Trends and Challenges for the Spectrum Efficiency in NOMA and MIMO based Cognitive Radio in 5G Networks
CN114244405A (en) Cooperative unicast and multicast mixed transmission method, system and application
He et al. QoS driven multi-user video streaming in cellular CRNs: The case of multiple channel access
Liu et al. Special Issue on Next Generation Multiple Access—Part I

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant